The present invention relates to a system for correcting the position of a spindle of a processing machine such as, an engine lathe, a grinding machine and others.
When a spindle of a processing machine is rotated in operation, frictional heat generates in the spindle. Particularly, in the case of the spindle which is supported by hydrostatic bearings, the temperature of lubricating oil in the pockets elevates by friction so that the temperature of the spindle also rises. Therefore, the spindle thermally expands in the axial direction, which causes a positioning error or deviation in distance between a tool and a work.